Characteristics of GaN-Based LEDs With Hybrid Microhole Arrays and SiO2 Microspheres/Nanoparticles Structures

The Characteristics of GaN-based LEDs with hybrid microhole arrays and SiO2 microspheres (MSs)/nanoparticles (NPs) are comprehensively studied. The SiO2 MSs/NPs antireflection coating, deposited by a rapid convection deposition, acts as a passivation layer of GaN-based LEDs. Since the critical angle could be enlarged by antireflection coating, Fresnel reflection could be reduced. In addition, due to the roughened surface of SiO2 MSs/NPs antireflection coating, the scattering effect could also be increased. Thus, the light extraction efficiency could be further enhanced. As compared with a conventional LED with a planar aluminum-doped zinc oxide current spreading layer (Device A), the studied device with the proposed hybrid structure and a sputtered SiO2 passivation layer (Device E) causes a suppressed leakage current and % enhancements on light output power, external quantum efficiency, and wall-plug efficiency performance.